html,body{
    width: 100%;
    height: 100%;
    background-color: #ddd;
}
.menu_top{
    width: 100%;
    height: 45px;
    background: url("../images/header-bg.png") repeat-x;
    background-size: 1px 44px;
    border-bottom: 1px solid #ddd;
    position: fixed;
}
.menu_top_back{
    width: 40px;
    height: 40px;
    position: absolute;
    top: 0;
    left: 0;
    padding: 10px;
    background: url("../images/sprites.png") no-repeat;
    background-size: 200px 200px;
    background-position: -20px 0;
    background-clip: content-box;
    background-origin: content-box;
}
.menu_top_search{
    width: 100%;
    height: 45px;
    padding:0 40px;
}
.menu_top_search>input{
    width: 100%;
    height: 35px;
    margin-top: 3px;
}
.menu_top_menu{
    width: 40px;
    height: 40px;
    position: absolute;
    top: 0;
    right: 0;
    padding: 10px;
    background: url("../images/sprites.png") no-repeat;
    background-size: 200px 200px;
    background-position: -60px 0;
    background-clip: content-box;
    background-origin: content-box;
}
.menu_b{
    width: 100%;
    height: 100%;
    padding-top: 45px;
    background-color: red;
}
.menu_b_left{
    width: 90px;
    height: 100%;
    overflow: hidden;
    position: relative;
}
.menu_b_left>ul{
    position: absolute;
}
.menu_b_left>ul>li>a{
    display: block;
    width: 90px;
    height: 40px;
    font: 16px/40px 'microsoft yahei';
    text-align: center;
    border: 1px solid #ccc;
    background-color: #fff;
}
